import java.io.*;

public class e01 {
 public static void main (String [] args) {
  InputStreamReader isr = new InputStreamReader(System.in);
  BufferedReader br = new BufferedReader (isr);
//Cambio de prueba.
  try {
   System.out.print("Base: ");
   int b = Integer.parseInt(br.readLine());
   System.out.print("Altura: ");
   int a = Integer.parseInt(br.readLine());
   System.out.println ("Área: " + b*a/2);
  }
  catch (Exception e) {
   e.printStackTrace();
  }
 }
}
